What’s a tree in Toronto worth? About $700, according to a special report from TD Economics.

Toronto’s urban forest doesn’t just make the city look pretty. This green space is a “critical factor” in the environment, human health, and overall quality of life, TD Economics said.

“An investment in urban forests is an investment in the overall economic and environmental well-being of urban society,” according to the report, released Monday.

The study shows that Toronto’s greenery provides residents with over $80 million – about $8 per tree – worth of environmental benefits and cost savings each year.

For the average single family household, that’s about $125 of savings from rain and snow cover, removed air pollutants, and saved heating and cooling costs, among other benefits.

When cost is added to the equation, trees are still well worth the investment, TD Economics said.

For every dollar spent on annual maintenance, Toronto’s urban forest returns anywhere from $1.35 to $3.20 worth of benefits and cost savings each year.

“The cost savings produced by our urban forests make it clear that keeping the green on our streets, keeps the green in our wallets,” senior economist Craig Alexander and economist Connor McDonald wrote in the report.

The study report is being applauded by environmental groups.

“We’ve had urban forest advocates talking about this for some time but to have a bank economist come out with this is quite exciting,” said Janet McKay, founder and executive director of Local Enhancement and Appreciation of Forests, a non-profit group known as LEAF.

“This is a very strong argument for provincial and federal investment in the preservation and maintenance and improvement of our urban forests.”

The report does not begin to put a value on many other benefits – aesthetic value, recreational spaces, community importance – of the urban forest, Alexander said.

“We’re probably deeply underestimating the value simply because there are a lot of non-tangibles that there’s no way we could actually put a price to,” he said.

“What’s the value of trees in a park providing shade in the summer when a family is there and the kids are playing? You can’t put a value on that.”

The report pegs the replacement value, what it would cost to remove a tree and replant a similar one, at over $700 billion, or about $700 per tree.

Urban forests help ease the burden of managing snow and rain by intercepting precipitation, increasing the amount of water absorbed in the ground and reducing soil erosion, the report said.

This wet-weather flow reduction saves the city about $50 million each year, the report said.

Trees also produce oxygen, absorb air pollution, and capture dust, ash, dirt and pollen in their canopies.

Toronto’s urban forest removes about one-quarter of the emissions produced by industry within the city – about 19,000 metric tons of air pollution removed from the atmosphere annually.

That means the urban forest pulls out the particulate matter equivalent to what’s released by over 1 million automobiles each year, TD said.

Greenery also lowers energy demand for cooling and heating – which means savings for households and businesses. The net cooling effect of a young healthy tree is equivalent to ten room-sized air conditions operating 20 hours a day, the report said.

Toronto’s urban forest is comprised of approximately 10 million trees, shrubs, and other flora and fauna that line the streets, parks, and ravines of the city. It includes at least 116 different species, the report said.

Not all trees are created equal, and the benefits they provide vary, depending on size and species, the report said.

“But as a general rule of thumb, we can say bigger is better. Large, healthy trees absorb up to 10 times more air pollutants, 90 times more carbon, and contribute up to 100 times more leaf area to our urban forest canopy relative to smaller trees,” the report said.

Smaller plants pull their weight, too, contributing about one-quarter the air quality benefits that trees do, the TD said.

According to Toronto’s 2011 budget, the annual maintenance cost of a tree is roughly $4.20.

Street trees, which are among the most difficult to grow and maintain, return about $1.35 of benefits for every dollar spent, the report said.

The urban forest covers nearly 30 per cent of Toronto, about 190 square kilometers, and most of it is located in ravines and river valleys such as the Don Valley, Highland Creek, and Rouge River watersheds, which have been largely undisturbed by the city’s expansion.

But other serious threats are lurking, including invasive species, such as the European Gypsy Moth and the Emerald Ash Borer, as well as the Asian Long Horned Beetle, thought to be eradicated in Canada, but re-discovered in western Toronto in October, 2013.

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